In terms of Matrix IDs, we very very deliberately made up the @user:example.com format to avoid folks ever confusing them with email addresses like [email protected] (and to hint at a federated form of @mention notation, a bit like ActivityPub subsequently did). We find it super confusing that SIP URIs and JIDs look like [email protected] if you drop the scheme prefix (as often happens), given there's zero reason why [email protected] on email should be configured to correctly route to the same entity as sip:[email protected] or xmpp:[email protected] - and in fact the chance of it working in the general case are incredibly low (thanks to aliases, filters, routing rules, etc).
That said, we do not expect Matrix IDs to be used in the general case - we've always wanted people to discover each other based on their existing identifiers (email, phone number, etc). In practice this hasn't gone smoothly as nobody has properly solved decentralised identity (or if they have, they haven't hooked it up to Matrix yet), so we're in a bit of a limbo. But the solution is definitely not to make Matrix IDs look like email addresses.
So, my point here is that this is not "technically correct is the best kind of correct". If we renamed Riot to be "Matrix Client" we'd be quite rightly crucified by every other Matrix client developer out there. Just like Mozilla would if they renamed Firefox to be "Web browser" (even though they were effectively responsible for the modern web browser as Netscape).
However, we absolutely have made things even more unnecessarily complicated by maintaining separate brands for Riot, Modular and New Vector, hence consolidating them together. But we simply can't get away from the fact that the end result will be a Matrix client, not the Matrix client.
If I could wave a magic wand, formatting matrix usernames as “[email protected]” instead of “@alice:alice.com” feels like a similar opportunity to make things more friendly to newcomers.
It’s these little things that make a huge difference to success. TL=com/ORG=ycombinator/HOST=news addressing vs news.ycombinator.com. Or calling Outlook an “MUA” instead of just saying it’s a “mail client”.
It’s technically correct. Some people say that technically correct is the best kind of correct, but often it feels like the most convincing strategy is the one where you don’t need to add explanation or bon mots to win over opinion — people can just see it’s right.
I’m surprised that Matrix didn’t think they would benefit from trying to become well known as Matrix first, then diversify into FluffyChat etc second.